1. Field of the Invention
The present invention relates to display apparatus for use in a hybrid vehicle comprising an electric motor for locomotion and an engine.
2. Description of the Related Art
A hybrid vehicle comprises an electric motor for locomotion and an engine. The hybrid vehicle is configured to switch between locomotion using the electric motor alone and hybrid locomotion using both the electric motor and the engine or locomotion using the engine alone in accordance with locomotion conditions and others.
As an example of the hybrid vehicle, the hybrid vehicle may carry out control of disabling the engine to effect locomotion using the electric motor alone when the extent of depressing an accelerator pedal is small or switching to hybrid locomotion when an accelerator operation amount has increased beyond a fixed level.
Further, a display apparatus is known. This display apparatus displays an electric motor locomotion zone and a hybrid locomotion zone in a background of a meter configured to indicate locomotion situations of a vehicle. Furthermore, an indicator moves between the electric motor locomotion zone and the hybrid locomotion zone in accordance with an accelerator operation amount. In this type of display apparatus, the indicator indicates the electric motor locomotion zone when the accelerator operation amount is small. Moreover, the indicator moves to the hybrid locomotion zone when the accelerator operation amount increases. This type of technology is disclosed in, e.g., Japanese Patent Publication No. 4155321 and Japanese Patent Publication No. 4251210.
Based on this technology, a driver can roughly recognize a distance for which the vehicle can travel by the electric motor locomotion alone based on a width of the electric motor locomotion zone.
On the other hand, the electric motor locomotion zone and the hybrid locomotion zone are displayed in the background of the meter configured to indicate a locomotion situation of the vehicle. A ratio of the electric motor locomotion zone and the hybrid motor locomotion zone is mainly determined based on a maximum output value that can be output from a battery.
Specifically, since the electric motor locomotion is possible even though the accelerator pedal is greatly depressed when the maximum output value from the battery is sufficiently high, the large width of the electric motor locomotion zone is set. Since the hybrid locomotion is carried out when the maximum output value from the battery is reduced, the width of the hybrid locomotion zone is enlarged. Therefore, the width of the electric motor locomotion zone is reduced.
However, as characteristics of the battery, the maximum output value of the battery is relatively hardly changed irrespective of the state of charge (SOC). Moreover, the maximum output value of the battery tends to be reduced as the SOC is extremely reduced. That is, when the SOC is extremely reduced, the electric motor locomotion zone is precipitously decreased. It is to be noted that, in other words, the SOC is a remaining battery capacity.
Therefore, it is difficult for the driver to appreciate a type of locomotion that will be effected by the electric motor alone. In other words, if locomotion will be continued, a relationship between a future locomotion distance and an accelerator operation amount required to continue the electric motor locomotion mode is hard to be appreciated.